Cast iron is easy to weld, if you have access to an arc welder you can do it, they sell special rods at the welding shop, just put the head in the oven on broil for a couple of hours, to preheat it, get it nice and hot,well over 500 if possible, then hit it with the rod, do your welding, then put it back in the oven, and slowly let it cool, or you can put it in a container with oil to let it slowly cool, the main key is in your preheat and postheat, and hey if you mess it up you did not screw up a good part, your already in the hole, so at least you get some practice